Grinder



`July 31, 1928. 1,619,182

H. J. sHEL- roN GRINDER 4Filed Nov. '7, 1927 2 Sheets-Sheet l INVENTOR ATTORNEY GRINDER Filed` New, 7, 1927 2 sheets-sheet INVEyR @if ATTORNEY Patented July 31, 1928.

vUN ITED ATES HARRY J'. SHELTON, .0F UNIVERSITY CITY, MISSOURI.

GRINDER.

Application led November 7,y 1927. Serial No. 231,547.

My invention relates to certain new and useful improvements in grinders for grain, and other suitable material, the peculiarities of which will be hereinafter described 5 and claimed.

' The main object of my invention is to provide a screen mounting in a grinder of lthe class described, that 4will afford ready access to: the screen for changing it while lo the grinder is ruiming, and avoid loss-of time and expenditure of power. from frequent stopping. In grinding grain of various kinds, it is necessaryto use a screen having perforationsof asize corresponding to 15 the tineness desired. --When such a grinder is used forgeneral grist'mill worin-for eX- lample, a load ofwheatmay follow one of "cob corn or other coarse material. An appropriate screen must be employed for each material, and 'frequent' changes of' screen are made. Usually the ygrinder must` be stopped to change the screen. Though the power is shut off, the heavy cylinder of discs and hammers continues tofrotate. for several lmiiiiuzeswactually fifteen minutes in some cases. Again, after the changeofscreens has been effected, the starting torque of one anda half-to twice the runningamperage, yuses powerwithout accomplishing useful work of grinding.` I propose to short-enthe time of changing screens to a minimum. and avoid stopping the grinder, by the construction now to be described.

In the accompanyingdrawings on which like reference numerals .indicate corresponding parts, Fig. 1 represents a vertical central section across the shaft and casing of a grinder having my improvementszin operative position applied thereto; Fig. 2, a plan -view lof my improved screen frame 4with a portion of afscreen thereon; Fig. 3, a.` detail top and .end View of my inner end .ba-r for such frame; Fig. 4, a section similar to Fig. 1, but on a reduced scaleand with my screen frame withdrawn from the grinder for changing the screenthereon; 'and Fig. 5, a vertical section on the vline 5-5of Fig. 4, showing the screen in operativer position.

Referring to thedrawings, the numeral 1 designates the sha-ftof agrinder of they class described, on `which are. mounted-*discs 2 having hammer rods 3 to which arepiv-` oted hammers 4 constituting the cylinder -f and rotatingin thev direction of the arrows..y A casing therefor consists of lower sides 6 vsaid groove. .ducedy to fo-rm shoulders andipassthrough r.against the ribs 17, or otherwise.

having atl one end van opening 7 with a door 8 set against a shoulder or otherwise, `and secured by a. wedge bar 9 at the top, as shown in Fig. 1. Theopposite end is closed by a spacer plate 10. Upper sid-es 11 connected. Vco

by curved front and backplates 12 and .13

with grinding plate 14, form a cover preferably hinged at 15, and a feed inlet 16. A semi-circular rib 17 concentric-.with the shaft projects inward from each lower side, forni- .c5 ing a shoulder to engage. the `top of an arcnate screen 18, supported by a corresponding frameconsisting of side pieces 19, connected by rods 2() with pipe spacers,and c ross bars 21 and 22 at the endso'f the semi- -70 circle. The bar 21 is preferably `iush 4with thefupper face of the side pieces-and fastened to the sides by machine screws 23y or otherwise. Thev bar 22 adjacent the grinding plate projects inward substantially to T5 the cylindrical plane of the inner'face of the screen, and has a groove on its lower side forming a lip 24 to hold the upper edge of the screen and prevent feed being wedged beneath it. The'upper faces of the sides 19 s0 are inclined or recessed outward near the bar 22, to admitthe adjacent screen edge to Theends of A.thebar are vreholes in the side pieces; they are prevented `e5 from turning by rivets or otherwise, while extensions, integral or otherwise,y project laterally from the side pieces and formV pins v25 that enter groves 2G inthe lowerside of thecasing and guide the inner end of than@ vvframe and screen by a sliding and 'pivotal engagementtherewith, when the fastening devices free the screen and frame from-the operative position.

These fastening .devices preferably con- .o5 sist of a. spring catch at each end ofthe vfra-me,automatically engaging each cross bar vwhen in operative position and holding the screen firmly in operative position The rear I loo or inner catch preferably consists of a strut 27, pivoted at its lower endtov the spacer plate 10 and slightly beveled at its upper end to engage the und-er side of the` cross bar 22 with a wedge action under the pres-V105 sureof a spring28. A yrod29 is pivoted to the strut and extends through a hole in the back pla-te'tothe outside, for use as a-.handle to disengage the strut from Vthe cross :bar 22 as indicated by dotted lines in Fig. 1. A H0 cross pin 30 in the rod limits the inward movement ot the strut under the tension ot the spring, so that its end will be in the path of the bar 22 as shown in Fig. A.

The other end bar 2l is also preferably held in operative position by an automatic catch, such as a spring 3l riveted to an angle spacer 32 of the cover, and extending down past the bar 2l where it ends in a beveled hook 33 adapted to secure this end of the frame and screen in operative position. 'Ihe door 8 backs against this catch and is firmly held by the wedge bar 9 to prevent accidental disengagement of the catch.

These guiding grooves 26 are beyond and below the ribs 17, and are suitably curved as they pass from the central plane at the rear to the door opening at the front ot the grinder, so as to `allow the screen and frame to be withdrawn from the casing as shown in Fig. a. The screen can then be easily and safely removed from the trame and another put in place. The outer end ot the trarne is then raised as indicated by dotted lines in Fig. 4, and a quick shove assisted by the weight of the trame, slides the pins 25 to the rear and upper end ot the guiding grooves 26, where the strut 27 is snapped under the bar 22, as shown. The front end bar 2l is thenV raised till it is engaged by the hook end 33. i

The inner upper corner of the bar 22 is rounded to avoid interference with the rotating hammers under the pivotal movement about the pins 25. Also the grooves 26 are preferably located so that only the upper rear ends of the grooves approach the hammers to guide the bar 22 to operative position, while the Alower and front portions of the grooves diverge from the hammers and guide the bar 22 outward to the dooropening. The front ends of the slots 26 are preferably provided with a stop bolt 34 to prevent the pins 25 leaving the grooves when the frame is drawn out as shown in Fig.. and thus facilitate returning it to operative position.

While I have shown and described the screen and frame as being withdrawn through a door opening at the front of the grinder, the door opening may be in the rear if desired, and the screen and frame withdrawn accordingly.

I cla-im: Y n

1. A grinder of the class described comprising rotary hammers, a. casing having an end door and side casing grooves adjacent to the hammers, an arcuate screen and supporting frame detacha'oly mounted in the casing adjacent to the hammers-one end of said frame having side projections engaging the side casing grooves and vforming a sliding pivotal engagement with the casing allowing withdrawal through the endopening-and means to secure the screen and trame in operative position.

2. A grinder of the class described, comprising rotary pivoted hammers7 a casing having an end door opening, a door for said opening, an arcuate screen and supporting trame detachably mounted adjacent to the hammers and one end adjacent to said door, and an interposed spring catch adapted to engage said end and backed up by the door when closed preventing disengagement until opened.

3. A grinder oi the class described, com prising rotary hammers, a casing having an end opening, an arcuate screen and Supporting frame detachably mounted adjacent to the hammei's-the inner end oit' the trame having a sliding pivotal engagement with the casing-a catch engaging said end in operative position and having an extension outside the casing to release the catch, and means to secure the other end ot said frame in operative position.

Ll. A grinder ot the class described, comprising rotary hammers, a casing having an end opening and inside grooves, an arcuate screen and supporting trame detachably mounted adjacent to the hammersthe inner end of the frame having lateral projections in sliding pivotal enga-gement with said inside grooves-the inner ends of the inside grooves' approaching the hammers to guide the screen and trame to operative position, and the outer ends of said grooves diverging from the hammers to facilitate its withdrawal from the casing through said end opening,

5. A grinder of the class described, comprising rotary hammers, a casing having a door opening and arcuate inside grooves, an arcuate screen and supporting frame detachably mounted adjacent to the hammerssaid frame having arcuate sides and end bars supporting the respective sides and ends of said screen the inner end bar having extensions projecting through the sides into the arcuate side grooves of the casing forming a sliding pivotal engagement with the casing, substantially as described.

6. A grinder of the class described, comprising rotary hammers, a cooperating grinding plate, a casing therefor, an arcuate screen and supporting frame having arcuate sides and connecting end bars-the end bar adjacent to the grinding plate having on its underside a groove forming a lip for the inserted end of the screen-the inner face of the trame near said end being inclined outward to facilitate insertion of the screen in said groove.

VIn testimony whereof I have alixed my signature.

Y HARRY J. SHELTON. 

